Jul. 09, 2011

By Sharon Klotz

One of the things that’s surprising about a shuttle launch is that, while our mental images of the event are usually integrated storylines, the experience itself actually isolates and disambiguates each sensory channel. The syncopated inputs first arrest the eyes, then overwhelm the ears, then rock through every atom in our bodies before leaving us -- momentarily and then for all eternity -- completely warmed, hollowed out, and in utter surrender.

The visual radiance of the launch owes its color and intensity to the combustive chemical constituents that fuel the energy transformations providing the shuttle’s upward lift. As those compounds interact, their extreme temperature and massive energy -– the very elements that explain why the press site, the closest possible vantage point, is 3 miles from the Launchpad –- register to our eyes as a cartoon-like, metallic radiance one might liken to the Sun. Unlike the Sun, though, the shuttle’s red-orange-yellow plume streaks upward from our shared horizon line. The fire that holds our eyes begins in a familiar plane but then quickly turns our heads toward the spatial axis with which we’re least familiar.

Photo credit: Wayne LaBar

Light travels nearly 900,000 times faster than sound. By the time our ears receive and register the longitudinal pressure waves sparked by the compressive forces of launch, the shuttle has already made considerable progress upward. Because of this lag, the shuttle’s sound tracks “lower” in the sky than its visual input, a sensory dissonance that contributes to the feeling that a launch somehow pulls us apart, unzips us from our normal experience. The shuttle’s sound frequency profile depends on many moving parts and on the shape of the launchpad housing. These factors combine to produce an undifferentiated, naturalistic sound rather than a highly focused or machined sound - more like a rumbling storm and less like a finely-tuned instrument. After a period of silent-movie action, the intense leading edge of the pressure wave hits, and the broad-frequency mix powers into and through our ears. By the way, the high-intensity water jets released during launch aren’t there to suppress fire; they’re there to suppress sound.

Just as our ears sense vibration, so, too, do our entire bodies. Everything we’re made of is vibrating, including our atomic and sub-atomic building blocks. We’re wired to “feel” sound as well as to hear it. As we’re craning up to follow the shuttle plume, we eventually hear the concomitant explosion of sound, and then we’re hit from the side by a rhythm of vibration that plays our skin like a drum. Long after the shuttle is out of view, we’re still dancing to the energy of its launch -- dancing from the inside out. In that state, we’re also still absorbing the thermal radiation thrown off by the shuttle’s ascent, and we’re riveted by the oversized atmospheric sculpture the shuttle’s trail imprints on the sky.

Before we can assemble and understand what we’ve just witnessed, we’ve been dis-integrated -- broken into our component senses –- and reconstituted anew. This is what leaves us reeling. This is what opens spaces filled by tears. This is how materials, fire, energy, physics, and engineering combine to bring us the experience –- the non-verbal, sensory, kinesthetic, visceral experience –- of hope.

______________________Sharon Klotz is an educational consultant who is attending the last launch of Space Shuttle Atlantis at NASA’s Kennedy Space Center in Florida.